Faunal Succession in Carboniferous Limestone. 467 
In this investigation the chief interest, from a zonal standpoint, 
centres in the occurrence of a higher faunal level than is known from 
any other point of the South-Western Province. The level here 
referred to is that of the Oystermouth Beds, of which the well-known 
Bishopston rotten-stones are the degraded representatives. The list 
of genera from these beds is practically identical with that from the 
Upper ‘Tournaisian—a fact which may be taken to imply equivalence 
of environment. Important conclusions as to variation in time during 
the Viséan period have therefore been reached by comparing the 
several species of each genus at the Oystermouth level (uppermost 
Viséan) and those of the same genus in the Upper Zaphrentis-zone 
(Upper Tournaisian). The comparison of these two levels determines 
those characters of each genus which are indicative of old age; whereas 
the comparison of the Brachiopods (or of the Corals) at one and the 
same level determines those characters which are affected by con- 
vergence. 
Mr. Dixon’s careful study of the conditions of deposition which are 
implied by the several lithic types increases very greatly the value of 
the zonal investigation by preventing the error of mistaking a change 
of fauna with change of conditions for a true zonal sequence dependent 
upon evolution. 
2.—The Carboniferous Sequence from Rush to Skerries, Co. Dublin. 
(In conjunction with Dr. C. A. Mattey.) 
The stratigraphical relations have been admirably worked out by 
Dr. Matley, in spite of a quite remarkable intricacy of tectonic detail. 
From a zonal point of view the main subject of inquiry is the true 
relative position of four distinct series whose sequence with one 
another is broken either by faults or gaps. The problem has been 
solved by a broad comparison of the coral faunas and their sequence 
in the South-Western Province. The relative position of the several 
portions has thus been established, and it has consequently become 
possible to draw up a detailed faunal sequence for the whole section. 
This sequence starts in the Upper Tournaisian, and extends beyond 
uppermost Avonian, being, however, notably incomplete in its middle 
portion. 
The highest beds, which still exhibit an abundant Avonian fauna 
(the Upper Cyathaxonia beds), include a maximum of Posidonomya 
Bechert, and at the same time contain several strikingly specialised 
forms of Corals and Brachiopods which also occur in the Lower Lime- 
stones of Scotland and in the uppermost Limestones of the western 
Midlands and Settle. Much light has thus been thrown upon the 
true correlation of the uppermost Avonian rocks in widely distant 
areas. 
These results will be published at an early date. 
3.—Paleontological Work. 
The paleontological work arising out of these two papers has been 
very considerable, and is as yet incomplete. 
Minute study of the material collected, and comparison with that 
already gathered from the South-Western Province and other British 
